1 /*
2 * EAP-IKEv2 peer (RFC 5106)
3 * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10
11 #include "common.h"
12 #include "eap_i.h"
13 #include "eap_common/eap_ikev2_common.h"
14 #include "ikev2.h"
15
16
17 struct eap_ikev2_data {
18 struct ikev2_responder_data ikev2;
19 enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
20 struct wpabuf *in_buf;
21 struct wpabuf *out_buf;
22 size_t out_used;
23 size_t fragment_size;
24 int keys_ready;
25 u8 keymat[EAP_MSK_LEN + EAP_EMSK_LEN];
26 int keymat_ok;
27 };
28
29
eap_ikev2_state_txt(int state)30 static const char * eap_ikev2_state_txt(int state)
31 {
32 switch (state) {
33 case WAIT_START:
34 return "WAIT_START";
35 case PROC_MSG:
36 return "PROC_MSG";
37 case WAIT_FRAG_ACK:
38 return "WAIT_FRAG_ACK";
39 case DONE:
40 return "DONE";
41 case FAIL:
42 return "FAIL";
43 default:
44 return "?";
45 }
46 }
47
48
eap_ikev2_state(struct eap_ikev2_data * data,int state)49 static void eap_ikev2_state(struct eap_ikev2_data *data, int state)
50 {
51 wpa_printf(MSG_DEBUG, "EAP-IKEV2: %s -> %s",
52 eap_ikev2_state_txt(data->state),
53 eap_ikev2_state_txt(state));
54 data->state = state;
55 }
56
57
eap_ikev2_init(struct eap_sm * sm)58 static void * eap_ikev2_init(struct eap_sm *sm)
59 {
60 struct eap_ikev2_data *data;
61 const u8 *identity, *password;
62 size_t identity_len, password_len;
63
64 identity = eap_get_config_identity(sm, &identity_len);
65 if (identity == NULL) {
66 wpa_printf(MSG_INFO, "EAP-IKEV2: No identity available");
67 return NULL;
68 }
69
70 data = os_zalloc(sizeof(*data));
71 if (data == NULL)
72 return NULL;
73 data->state = WAIT_START;
74 data->fragment_size = IKEV2_FRAGMENT_SIZE;
75 data->ikev2.state = SA_INIT;
76 data->ikev2.peer_auth = PEER_AUTH_SECRET;
77 data->ikev2.key_pad = (u8 *) os_strdup("Key Pad for EAP-IKEv2");
78 if (data->ikev2.key_pad == NULL)
79 goto failed;
80 data->ikev2.key_pad_len = 21;
81 data->ikev2.IDr = os_malloc(identity_len);
82 if (data->ikev2.IDr == NULL)
83 goto failed;
84 os_memcpy(data->ikev2.IDr, identity, identity_len);
85 data->ikev2.IDr_len = identity_len;
86
87 password = eap_get_config_password(sm, &password_len);
88 if (password) {
89 data->ikev2.shared_secret = os_malloc(password_len);
90 if (data->ikev2.shared_secret == NULL)
91 goto failed;
92 os_memcpy(data->ikev2.shared_secret, password, password_len);
93 data->ikev2.shared_secret_len = password_len;
94 }
95
96 return data;
97
98 failed:
99 ikev2_responder_deinit(&data->ikev2);
100 os_free(data);
101 return NULL;
102 }
103
104
eap_ikev2_deinit(struct eap_sm * sm,void * priv)105 static void eap_ikev2_deinit(struct eap_sm *sm, void *priv)
106 {
107 struct eap_ikev2_data *data = priv;
108 wpabuf_free(data->in_buf);
109 wpabuf_free(data->out_buf);
110 ikev2_responder_deinit(&data->ikev2);
111 os_free(data);
112 }
113
114
eap_ikev2_peer_keymat(struct eap_ikev2_data * data)115 static int eap_ikev2_peer_keymat(struct eap_ikev2_data *data)
116 {
117 if (eap_ikev2_derive_keymat(
118 data->ikev2.proposal.prf, &data->ikev2.keys,
119 data->ikev2.i_nonce, data->ikev2.i_nonce_len,
120 data->ikev2.r_nonce, data->ikev2.r_nonce_len,
121 data->keymat) < 0) {
122 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to "
123 "derive key material");
124 return -1;
125 }
126 data->keymat_ok = 1;
127 return 0;
128 }
129
130
eap_ikev2_build_msg(struct eap_ikev2_data * data,struct eap_method_ret * ret,u8 id)131 static struct wpabuf * eap_ikev2_build_msg(struct eap_ikev2_data *data,
132 struct eap_method_ret *ret, u8 id)
133 {
134 struct wpabuf *resp;
135 u8 flags;
136 size_t send_len, plen, icv_len = 0;
137
138 ret->ignore = FALSE;
139 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Generating Response");
140 ret->allowNotifications = TRUE;
141
142 flags = 0;
143 send_len = wpabuf_len(data->out_buf) - data->out_used;
144 if (1 + send_len > data->fragment_size) {
145 send_len = data->fragment_size - 1;
146 flags |= IKEV2_FLAGS_MORE_FRAGMENTS;
147 if (data->out_used == 0) {
148 flags |= IKEV2_FLAGS_LENGTH_INCLUDED;
149 send_len -= 4;
150 }
151 }
152 #ifdef CCNS_PL
153 /* Some issues figuring out the length of the message if Message Length
154 * field not included?! */
155 if (!(flags & IKEV2_FLAGS_LENGTH_INCLUDED))
156 flags |= IKEV2_FLAGS_LENGTH_INCLUDED;
157 #endif /* CCNS_PL */
158
159 plen = 1 + send_len;
160 if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
161 plen += 4;
162 if (data->keys_ready) {
163 const struct ikev2_integ_alg *integ;
164 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Add Integrity Checksum "
165 "Data");
166 flags |= IKEV2_FLAGS_ICV_INCLUDED;
167 integ = ikev2_get_integ(data->ikev2.proposal.integ);
168 if (integ == NULL) {
169 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
170 "transform / cannot generate ICV");
171 return NULL;
172 }
173 icv_len = integ->hash_len;
174
175 plen += icv_len;
176 }
177 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, plen,
178 EAP_CODE_RESPONSE, id);
179 if (resp == NULL)
180 return NULL;
181
182 wpabuf_put_u8(resp, flags); /* Flags */
183 if (flags & IKEV2_FLAGS_LENGTH_INCLUDED)
184 wpabuf_put_be32(resp, wpabuf_len(data->out_buf));
185
186 wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
187 send_len);
188 data->out_used += send_len;
189
190 if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
191 const u8 *msg = wpabuf_head(resp);
192 size_t len = wpabuf_len(resp);
193 ikev2_integ_hash(data->ikev2.proposal.integ,
194 data->ikev2.keys.SK_ar,
195 data->ikev2.keys.SK_integ_len,
196 msg, len, wpabuf_put(resp, icv_len));
197 }
198
199 ret->methodState = METHOD_MAY_CONT;
200 ret->decision = DECISION_FAIL;
201
202 if (data->out_used == wpabuf_len(data->out_buf)) {
203 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
204 "(message sent completely)",
205 (unsigned long) send_len);
206 wpabuf_free(data->out_buf);
207 data->out_buf = NULL;
208 data->out_used = 0;
209 switch (data->ikev2.state) {
210 case SA_AUTH:
211 /* SA_INIT was sent out, so message have to be
212 * integrity protected from now on. */
213 data->keys_ready = 1;
214 break;
215 case IKEV2_DONE:
216 ret->methodState = METHOD_DONE;
217 if (data->state == FAIL)
218 break;
219 ret->decision = DECISION_COND_SUCC;
220 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
221 "completed successfully");
222 if (eap_ikev2_peer_keymat(data))
223 break;
224 eap_ikev2_state(data, DONE);
225 break;
226 case IKEV2_FAILED:
227 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Authentication "
228 "failed");
229 ret->methodState = METHOD_DONE;
230 ret->decision = DECISION_FAIL;
231 break;
232 default:
233 break;
234 }
235 } else {
236 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Sending out %lu bytes "
237 "(%lu more to send)", (unsigned long) send_len,
238 (unsigned long) wpabuf_len(data->out_buf) -
239 data->out_used);
240 eap_ikev2_state(data, WAIT_FRAG_ACK);
241 }
242
243 return resp;
244 }
245
246
eap_ikev2_process_icv(struct eap_ikev2_data * data,const struct wpabuf * reqData,u8 flags,const u8 * pos,const u8 ** end)247 static int eap_ikev2_process_icv(struct eap_ikev2_data *data,
248 const struct wpabuf *reqData,
249 u8 flags, const u8 *pos, const u8 **end)
250 {
251 if (flags & IKEV2_FLAGS_ICV_INCLUDED) {
252 int icv_len = eap_ikev2_validate_icv(
253 data->ikev2.proposal.integ, &data->ikev2.keys, 1,
254 reqData, pos, *end);
255 if (icv_len < 0)
256 return -1;
257 /* Hide Integrity Checksum Data from further processing */
258 *end -= icv_len;
259 } else if (data->keys_ready) {
260 wpa_printf(MSG_INFO, "EAP-IKEV2: The message should have "
261 "included integrity checksum");
262 return -1;
263 }
264
265 return 0;
266 }
267
268
eap_ikev2_process_cont(struct eap_ikev2_data * data,const u8 * buf,size_t len)269 static int eap_ikev2_process_cont(struct eap_ikev2_data *data,
270 const u8 *buf, size_t len)
271 {
272 /* Process continuation of a pending message */
273 if (len > wpabuf_tailroom(data->in_buf)) {
274 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment overflow");
275 eap_ikev2_state(data, FAIL);
276 return -1;
277 }
278
279 wpabuf_put_data(data->in_buf, buf, len);
280 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes, waiting "
281 "for %lu bytes more", (unsigned long) len,
282 (unsigned long) wpabuf_tailroom(data->in_buf));
283
284 return 0;
285 }
286
287
eap_ikev2_process_fragment(struct eap_ikev2_data * data,struct eap_method_ret * ret,u8 id,u8 flags,u32 message_length,const u8 * buf,size_t len)288 static struct wpabuf * eap_ikev2_process_fragment(struct eap_ikev2_data *data,
289 struct eap_method_ret *ret,
290 u8 id, u8 flags,
291 u32 message_length,
292 const u8 *buf, size_t len)
293 {
294 /* Process a fragment that is not the last one of the message */
295 if (data->in_buf == NULL && !(flags & IKEV2_FLAGS_LENGTH_INCLUDED)) {
296 wpa_printf(MSG_DEBUG, "EAP-IKEV2: No Message Length field in "
297 "a fragmented packet");
298 ret->ignore = TRUE;
299 return NULL;
300 }
301
302 if (data->in_buf == NULL) {
303 /* First fragment of the message */
304 data->in_buf = wpabuf_alloc(message_length);
305 if (data->in_buf == NULL) {
306 wpa_printf(MSG_DEBUG, "EAP-IKEV2: No memory for "
307 "message");
308 ret->ignore = TRUE;
309 return NULL;
310 }
311 wpabuf_put_data(data->in_buf, buf, len);
312 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received %lu bytes in first "
313 "fragment, waiting for %lu bytes more",
314 (unsigned long) len,
315 (unsigned long) wpabuf_tailroom(data->in_buf));
316 }
317
318 return eap_ikev2_build_frag_ack(id, EAP_CODE_RESPONSE);
319 }
320
321
eap_ikev2_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const struct wpabuf * reqData)322 static struct wpabuf * eap_ikev2_process(struct eap_sm *sm, void *priv,
323 struct eap_method_ret *ret,
324 const struct wpabuf *reqData)
325 {
326 struct eap_ikev2_data *data = priv;
327 const u8 *start, *pos, *end;
328 size_t len;
329 u8 flags, id;
330 u32 message_length = 0;
331 struct wpabuf tmpbuf;
332
333 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, reqData, &len);
334 if (pos == NULL) {
335 ret->ignore = TRUE;
336 return NULL;
337 }
338
339 id = eap_get_id(reqData);
340
341 start = pos;
342 end = start + len;
343
344 if (len == 0)
345 flags = 0; /* fragment ack */
346 else
347 flags = *pos++;
348
349 if (eap_ikev2_process_icv(data, reqData, flags, pos, &end) < 0) {
350 ret->ignore = TRUE;
351 return NULL;
352 }
353
354 if (flags & IKEV2_FLAGS_LENGTH_INCLUDED) {
355 if (end - pos < 4) {
356 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Message underflow");
357 ret->ignore = TRUE;
358 return NULL;
359 }
360 message_length = WPA_GET_BE32(pos);
361 pos += 4;
362
363 if (message_length < (u32) (end - pos)) {
364 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Invalid Message "
365 "Length (%d; %ld remaining in this msg)",
366 message_length, (long) (end - pos));
367 ret->ignore = TRUE;
368 return NULL;
369 }
370 }
371
372 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Received packet: Flags 0x%x "
373 "Message Length %u", flags, message_length);
374
375 if (data->state == WAIT_FRAG_ACK) {
376 #ifdef CCNS_PL
377 if (len > 1) /* Empty Flags field included in ACK */
378 #else /* CCNS_PL */
379 if (len != 0)
380 #endif /* CCNS_PL */
381 {
382 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unexpected payload "
383 "in WAIT_FRAG_ACK state");
384 ret->ignore = TRUE;
385 return NULL;
386 }
387 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Fragment acknowledged");
388 eap_ikev2_state(data, PROC_MSG);
389 return eap_ikev2_build_msg(data, ret, id);
390 }
391
392 if (data->in_buf && eap_ikev2_process_cont(data, pos, end - pos) < 0) {
393 ret->ignore = TRUE;
394 return NULL;
395 }
396
397 if (flags & IKEV2_FLAGS_MORE_FRAGMENTS) {
398 return eap_ikev2_process_fragment(data, ret, id, flags,
399 message_length, pos,
400 end - pos);
401 }
402
403 if (data->in_buf == NULL) {
404 /* Wrap unfragmented messages as wpabuf without extra copy */
405 wpabuf_set(&tmpbuf, pos, end - pos);
406 data->in_buf = &tmpbuf;
407 }
408
409 if (ikev2_responder_process(&data->ikev2, data->in_buf) < 0) {
410 if (data->in_buf == &tmpbuf)
411 data->in_buf = NULL;
412 eap_ikev2_state(data, FAIL);
413 return NULL;
414 }
415
416 if (data->in_buf != &tmpbuf)
417 wpabuf_free(data->in_buf);
418 data->in_buf = NULL;
419
420 if (data->out_buf == NULL) {
421 data->out_buf = ikev2_responder_build(&data->ikev2);
422 if (data->out_buf == NULL) {
423 wpa_printf(MSG_DEBUG, "EAP-IKEV2: Failed to generate "
424 "IKEv2 message");
425 return NULL;
426 }
427 data->out_used = 0;
428 }
429
430 eap_ikev2_state(data, PROC_MSG);
431 return eap_ikev2_build_msg(data, ret, id);
432 }
433
434
eap_ikev2_isKeyAvailable(struct eap_sm * sm,void * priv)435 static Boolean eap_ikev2_isKeyAvailable(struct eap_sm *sm, void *priv)
436 {
437 struct eap_ikev2_data *data = priv;
438 return data->state == DONE && data->keymat_ok;
439 }
440
441
eap_ikev2_getKey(struct eap_sm * sm,void * priv,size_t * len)442 static u8 * eap_ikev2_getKey(struct eap_sm *sm, void *priv, size_t *len)
443 {
444 struct eap_ikev2_data *data = priv;
445 u8 *key;
446
447 if (data->state != DONE || !data->keymat_ok)
448 return NULL;
449
450 key = os_malloc(EAP_MSK_LEN);
451 if (key) {
452 os_memcpy(key, data->keymat, EAP_MSK_LEN);
453 *len = EAP_MSK_LEN;
454 }
455
456 return key;
457 }
458
459
eap_ikev2_get_emsk(struct eap_sm * sm,void * priv,size_t * len)460 static u8 * eap_ikev2_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
461 {
462 struct eap_ikev2_data *data = priv;
463 u8 *key;
464
465 if (data->state != DONE || !data->keymat_ok)
466 return NULL;
467
468 key = os_malloc(EAP_EMSK_LEN);
469 if (key) {
470 os_memcpy(key, data->keymat + EAP_MSK_LEN, EAP_EMSK_LEN);
471 *len = EAP_EMSK_LEN;
472 }
473
474 return key;
475 }
476
477
eap_ikev2_get_session_id(struct eap_sm * sm,void * priv,size_t * len)478 static u8 * eap_ikev2_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
479 {
480 struct eap_ikev2_data *data = priv;
481 u8 *sid;
482 size_t sid_len;
483 size_t offset;
484
485 if (data->state != DONE || !data->keymat_ok)
486 return NULL;
487
488 sid_len = 1 + data->ikev2.i_nonce_len + data->ikev2.r_nonce_len;
489 sid = os_malloc(sid_len);
490 if (sid) {
491 offset = 0;
492 sid[offset] = EAP_TYPE_IKEV2;
493 offset++;
494 os_memcpy(sid + offset, data->ikev2.i_nonce,
495 data->ikev2.i_nonce_len);
496 offset += data->ikev2.i_nonce_len;
497 os_memcpy(sid + offset, data->ikev2.r_nonce,
498 data->ikev2.r_nonce_len);
499 *len = sid_len;
500 wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Derived Session-Id",
501 sid, sid_len);
502 }
503
504 return sid;
505 }
506
507
eap_peer_ikev2_register(void)508 int eap_peer_ikev2_register(void)
509 {
510 struct eap_method *eap;
511 int ret;
512
513 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
514 EAP_VENDOR_IETF, EAP_TYPE_IKEV2,
515 "IKEV2");
516 if (eap == NULL)
517 return -1;
518
519 eap->init = eap_ikev2_init;
520 eap->deinit = eap_ikev2_deinit;
521 eap->process = eap_ikev2_process;
522 eap->isKeyAvailable = eap_ikev2_isKeyAvailable;
523 eap->getKey = eap_ikev2_getKey;
524 eap->get_emsk = eap_ikev2_get_emsk;
525 eap->getSessionId = eap_ikev2_get_session_id;
526
527 ret = eap_peer_method_register(eap);
528 if (ret)
529 eap_peer_method_free(eap);
530 return ret;
531 }
532